Stents are used as prostheses for expanding and holding open in tubular hollow organs such as blood vessels. Such stents generally have a latticelike or spiral-shaped structure of material webs. Between the material webs, regions free of material are formed, which make it possible for this structure to grow into the tissue at its implantation site. Such stents are described, for example, in DE-A 197 46 88.
In bendable vascular regions such as in the knee, the prostheses of the prior art have the problem that substantial pushing, pulling and twisting movements occur in the region of the bending by the stent. Furthermore, additional frictional forces also act there on the intima of the blood vessels. Moreover, the aforementioned resulting pushing, pulling and twisting movements weaken the material webs, so that breakage and individual detachments of stent fragments can occur. This, in turn, can lead to injuries to the vascular wall, a restenosis, for example by scar formation on the vascular wall, or even the triggering of an aneurysm. Embolisms can also be triggered by this.
In publication DE 600 30 705 T2 a catheter is described for implanting of a stent, having a sheath, while a multiple-piece stent can be present in the sheath. The multiple-piece stent consists of neighboring stent pieces, which are joined together by connection elements. When the stent is inserted into an artery, the connection element is physically separated from an adjacent stent piece by an expansion of the stent piece. However, an exact laying or placing of the individual stent piece is nearly impossible in this case, since such a physical separation of the stent pieces is not always uniform. What is more, there is the disadvantage that traces of the connection elements remain on the stent pieces in place, which in turn can contribute to injury of the vascular wall.